Dr. Whittemore Receives NH-INBRE Grant

September 6, 2013

Dr. Susan Whittemore

Biology Professor and 2012’s Distinguished Teacher Susan Whittemore has received a $69,169 NH-INBRE grant from Dartmouth College (with federal funding from the National Institutes of Health) for her project, Identification of Signaling Pathways Affected by Early Exposure to Prevalent PAHs. The study will allow Dr. Whittemore and her student researchers to continue their investigation into phenanthrene (PHE) and pyrene (PYR), two polyaromatic hydrocarbons (PAHs) that are known pollutants present in human milk and cord blood. Despite the fact that these pollutants are an environmental and human health concern, little study has been conducted on the developmental effects of these compounds, a gap that Dr. Whittemore’s study should help fill.

"We want to determine whether exposure to the two common, but poorly studied, pollutants, phenanthrene and pyrene (both are PAHs), during early development adversely affects pigmentation and the heart," Dr. Whittemore explained. "Human fetuses and infants are exposed to both of these pollutants, yet we know little about their actions. We hope that our studies using the early embryos of the African clawed frog, the lab rat of the amphibian world and an important model of vertebrate development, will inform us about any developmental impacts of exposure to either or both of these PAHs. Specifically, we hope to identify certain signaling pathways, important to normal development, that are altered with exposure."

PAHs are formed whenever organic material is burned incompletely, so they’re very prevalent in our environment. They’re created when products like coal, oil, gas, wood, and garbage is burned, and when meat is grilled. They’re found in exhaust fumes, tobacco smoke, and in some smoked meats and fish.

Dr. Whittemore is currently working with three students, Liz Masure, Beaufort Pyram, and Julia Pinette (Biology majors and juniors), and she employs a former student, Luke Hebert ’13. The research team will daily observe frog embryos that are raised in water containing phenanthrene and pyrene. They’ll measure the frogs’ heart rate, heart rhythm, and contractility and look at the number and shape of the skin cells that produce the brown-black pigment known as melanin. Development of the human and frog heart follow very similar patterns and humans also produce melanin. "So far we have seen some effects of these PAHs on the heart and on pigmentation, so we hope to find out how these PAHs are altering the normal functioning of these two systems." Dr. Whittemore said. "We are investigating PAH effects on the expression of certain genes, using an RT-PCR (real-time polymerase chain reaction) instrument, and on certain signaling pathways important to the heart and pigment-producing cells.” An RT-PCR instrument is used to amplify and simultaneously quantify a targeted DNA molecule.